The present invention relates to robot programming and teaching systems and, more particularly, to a robot programming system that provides a more accurate and efficient programming routine that is particularly well suited for off-line robot teaching systems.
Yamato et al., U.S. Pat. No. 5,488,689, the disclosure of which is incorporated herein by reference, relates to a robot operation training system wherein robot training may be started before the actual robot is manufactured or installed. The robot training system has a controller substantially the same as the actual robot controller and a personal computer for simulating the functions of the robot body. The functions to be performed by the robot are simulated by replacing the robot with the personal computer. The present inventor has, however, recognized that the Yamato et al. system is likely to be difficult to operate and inefficient because of the inherent limitations presented by replacing the tangible robot itself with a simulated robot displayed on a computer screen.
MacLaren et al., U.S. Pat. No. 5,617,515, the disclosure of which is incorporated herein by reference, teaches a system for controlling and programming a robot wherein a hand-held controller wand is utilized to provide an intuitive control input for real-time direction and programming of robot movement. The present inventor has, however, recognized that the MacLaren et al. system is likely to be difficult to operate accurately because a user must view the motion of a peripheral device, e.g., an end effector of an actual robot, to monitor how the movement of the controller wand translates into movement of a robot tool. Specifically, the user must move the controller wand while viewing the end effector of the robot to observe the correlation between the movement of the controller wand and an actual robot tool. Thus, direct visual contact of the controller wand must be continuously interrupted to monitor the movement of a robot tool in a robot configuration. The present inventor has recognized that the MacLaren et al. system is likely to lack reliability and be difficult to operate because the user is forced to rely solely upon visual observation of the peripheral device to position the robot tool. The controller wand itself does not provide an accurate indication of the manner in which the robot tool has been positioned. Finally, the present inventor has recognized that the MacLaren et al. system is likely to lack reliability and be difficult to operate because the position, and thus the translation, of the controller wand is not sensed. Rather, the roll, pitch, and yaw data of the controller wand are the only variables sensed by the system. The user is required to activate a button on the wand itself to represent translation of the controller wand. Specifically, although the roll, pitch, and yaw of the controller are sensed by conventional angular rate sensors, the actual position and translation of the controller wand is not monitored. The user induces translation of the robot's end effector by pointing the wand in a preferred direction and engaging a button on the controller wand.
Accordingly, there is a need for a robot programming system and method that provide a more accurate and efficient programming routine that is particularly well suited for off-line robot teaching systems, that does not merely replace the tangible robot with a simulated robot displayed on a computer screen, that does not require the user to view a peripheral device to monitor the movement of the controller wand, that does not force the user to rely solely upon visual observation of the peripheral device to position the robot tool, and that is not limited to sensing merely the orientation of a hand held controller.